TELECOM Digest Tue, 17 Jan 95 19:26:00 CST Volume 15 : Issue 39 Inside This Issue: Editor: Patrick A. Townson Call For Papers: JMLICS (Mehmet Orgun) Re: How to Keep Track of Calls on Busy (Caller ID on Busy)? (Seymour Dupa) Re: Prepaid Telephone Debit Cards (P1854) Re: Would You Believe More Rain on the Way? (Ted Hadley) Re: 10-XXX Codes (Lizanne Hurst) Re: Looking up Addresses and Phone Number From Just Names (Tony Waddell) Re: Cellular Phone Pricing Question (Andrew Laurence) Re: Anyone Have Experience With LDDS/Metromedia? (Paul Beker) Re: Anyone Have Experience With LDDS/Metromedia? (Dave Rand) Re: How Can I Encrypt a T-1? (Barton F. Bruce) Re: Bellcore Standards Question (Bill Mayhew) Re: Atlanta Airport's Pay Phones Reject 1-800 Numbers Randomly (John Rice) Re: Atlanta Airport's Pay Phones Reject 1-800 Numbers Randomly (B Thompson) Where Can I Buy Telephones (franci.visnovic@uni-mb.si) TELECOM Digest is an electronic journal devoted mostly but not exclusively to telecommunications topics. It is circulated anywhere there is email, in addition to various telecom forums on a variety of public service systems and networks including Compuserve and America On Line. It is also gatewayed to Usenet where it appears as the moderated newsgroup 'comp.dcom.telecom'. Subscriptions are available to qualified organizations and individual readers. Write and tell us how you qualify: * telecom-request@eecs.nwu.edu * The Digest is edited, published and compilation-copyrighted by Patrick Townson of Skokie, Illinois USA. You can reach us by postal mail, fax or phone at: 9457-D Niles Center Road Skokie, IL USA 60076 Phone: 708-329-0571 Fax: 708-329-0572 ** Article submission address only: telecom@eecs.nwu.edu ** Our archives are located at lcs.mit.edu and are available by using anonymous ftp. The archives can also be accessed using our email information service. For a copy of a helpful file explaining how to use the information service, just ask. ********************************************************************** *** * TELECOM Digest is partially funded by a grant from the * * International Telecommunication Union (ITU) in Geneva, Switzerland * * under the aegis of its Telecom Information Exchange Services (TIES) * * project. 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Any organizations listed are for identification purposes only and messages should not be considered any official expression by the organization. ---------------------------------------------------------------------- Date: Wed, 18 Jan 95 10:41:38 +1100 From: mehmet@macadam.mpce.mq.edu.au (Mehmet Orgun) Subject: Call For Papers: JMLICS Call for Papers The Journal of Methods of Logic in Computer Science Special Issue: Formal Methods in Logic for Responsive Systems A responsive computing system is one which responds to internal programs or external inputs in a timely, dependable and predictable manner. These systems are a hybrid of real-time, distributed, secure, safety-critical, and fault-tolerant systems. In such a system, any failure can cause catastrophes ranging from financial loss and loss of privacy to physical damage and loss of life. Thus, it is important to ensure that the system is not only correct, but remains correct at run time, under abnormal circumstances. The major difficulty facing designers is the complexity inherent in responsive computing systems. In practice, informal approaches are often used which can result in latent failures, under-specified systems, or inconsistencies. One way to counteract these problems is to bring the idea of rigor and formalism from traditional systems engineering fields into the development of software through the use of formal methods. Formal methods of logic, in particular, can be used to rigorously synthesize, specify, verify, debug, and model responsive computing systems. However, formal methods of logic are usually dismissed as the domain of academicians and viewed as irrelevant or not applicable to the design and implementation of large-scale software projects due to their mathematical complexity. To bring these two opposing camps together, work that emphasizes and reinforces the point that formal methods can, and should, be used in the practical construction of high quality, reliable distributed software is of interest. This special issue will bring together papers in the following areas that support the use of formal methods of logic in the construction of responsive computing systems: o Formal Specification/Verification/Refinement Techniques o Requirements Specification o Assertional Reasoning and Executable Assertions o Model Checking o Testing and Debugging (Predicate Detection) o Tool Support o Formal Semantics of Concurrency/Recovery o Compositional Proof Systems o Distributed Systems Security o Experience Reports Papers should, ideally, emphasize results that can be applied to the construction of actual responsive computing systems (although, work is in no way solely limited to experience reports). Please submit six copies of your manuscript to the guest editor by June 1, 1995: Bruce McMillin Computer Science Department (516)-632-8334 (FAX) State University of New York at Stony Brook (516)-632-8218 (Office) Room 1420 Computer Science Building (516)-632-8471 (Secretary) Stony Brook, NY 11794-4400 USA e- mail(bruce@cs.sunysb.edu) Instructions for submitting papers: Papers should not exceed 30 double spaced pages. Papers should not have been previously published, nor currently submitted elsewhere for publication. Papers should include a title page containing title, authors' names and affiliations, postal and e-mail addresses, telephone numbers and Fax numbers. Papers should include a 300 word abstract and 5-10 keywords and be written in the IEEE Transactions style. Each paper will be peer-reviewed by at least three referees. [Note: If you are willing to referee papers for this special issue, please send a note with your research interest to the guest editor.] Notification of acceptance will be sent by September 1, 1995; final versions will be due by October 15, 1995. The special issue will be published in the 2nd Quarter 1996. ------------------------------ From: grumpy@en.com (Seymour Dupa) Subject: Re: How to Keep Track of Calls on Busy (Caller ID on Busy)? Date: 17 Jan 1995 12:16:57 -0500 Organization: Exchange Network Services, Inc. Steve Cogorno (cogorno@netcom.com) wrote: > Ask your phone company for an analysis. They will do it, but maybe > not for for a residential customer, and it may not be free. I would think the phone company would be *happy* to do that report for you. This is the way the phone company can show their multi-line customers how many calls they are missing and take their order for more lines. ------------------------------ From: p1854@aol.com (P1854) Subject: Re: Prepaid Telephone Debit Cards Date: 17 Jan 1995 13:20:36 -0500 Organization: America Online, Inc. (1-800-827-6364) Reply-To: p1854@aol.com (P1854) Peter Pappas in Tampa 813-288-3253 is looking for prepaid cards for friend in Mass who wants to use for school financing. Any leads would be appreciated. ------------------------------ Date: Tue, 17 Jan 95 10:35:31 PST From: tedh@cylink.COM (Ted Hadley) Subject: Re: Would You Believe More Rain on the Way? Pat, > Well, good luck and my best regards, folks. It seems like the people > in California spend all summer burning the place down, then spend > all winter enduring mud slides and flooding. Thanks, but you forgot the earthquakes! :) I live near San Jose, and yes, we have had lots of rain. But there have been no real problems in the majority of the areas. Mudslides in the mountain passes and flooding where the cities left flood control work unfinished in the last few years and highway flooding where the routine maintenance wasn't. The only real problems were in Marin County along the Russian River and in Sacramento. Ted Hadley tedh@cylink.com ------------------------------ From: lh00@Lehigh.EDU (Lizanne Hurst) Subject: Re: 10-XXX Codes Date: 17 Jan 1995 15:20:24 -0500 Organization: Lehigh University Thanks for posting this information. However, I think one key point requires clarification. > According to a law that was passed in 1990, all aggregators must > unblock their switches so that a caller can reach their long distance > carrier of choice. What this required so that you wouldn't get stuck > paying for the cost of the calls was that your switch had to pass > through and differentiate calls that started with either 10-XXX-1 or > calls that started with 10-XXX-0. If you're referring to the Telephone Operator Consumer Services Improvement Act of 1990 (Public Law 101-435), aggregators (hospitals, hotels, universities) are required to unblock only 10-XXX-0 calls, *not* 10-XXX-1 calls. All the rest of your remarks are pretty much in line with the Act as I remember it. Additional information is available in the FCC's Report and Order, FCC 91-214. As a side note, ACUTA (the Association of College and University Telecommunications Administrators) lobbied unsuccessfully to overturn universities' classification as aggregators. An aggregator, as defined in this case, is an entity which provides service for the public and/or transient users; ACUTA challenged the assumption that student users are "transient." Lizanne Hurst Office of Telecommunications Lehigh University (610) 758-5014 ------------------------------ From: Tony Waddell Subject: Re: Looking up Addresses and Phone Number From Just Names Date: 17 Jan 1995 16:47:11 GMT Organization: Pacific Bell > [TELECOM Digest Editor's Note: I don't know how many you think is a > 'bunch', but unless it is really a lot, and you plan to do this on > a frequent basis, why don't you ask the telco serving the local calling > area for a copy of their directory. Most telcos will send it free of > charge, or they may get some small handling/postage fee. Then you would > sit there and look them up. After you have found all you can, then call > AC-555-1212 for the (hopefully) few remaining names. PAT] I'm not sure if this is PACBELL policy only, or whether it's fairly consistent across the country, but I wanted a phone book from my home town, Davenport, Iowa. I was quoted a charge in excess of $50! And its not even a very thick book. Naturally, I declined. Another alternative might be available. Don't most telcos offer a listing service? I seem to recall that you can mail a list of names to the business office and they will attempt to provide a phone number for each name providing the number is published (I don't know if they'll provide addresses), There was a charged for this, but I don't remember it as being excessive. ------------------------------ From: laurence@netcom.com (Andrew Laurence) Subject: Re: Cellular Phone Pricing Question Organization: NETCOM On-line Communication Services (408 261-4700 guest) Date: Tue, 17 Jan 1995 21:40:58 GMT weave@hopi.dtcc.edu (Ken Weaverling) writes: > In article , John McGing digex.net> wrote: >> Anyway, I have a couple of questions: Even including the $25.00 year >> to the employee association, the monthly base cost is $11.03 month vs >> $24.95. Over three years that's $167.00 x3 or over $500.00 in >> savings. Is this deal too good to be true? The three year thing >> doesn't worry me (we're NOT moving and the car phone we have is a >> real top drawer Motorola we can switch to a new car.). Should it? > One of the reasons for a three year contract may be due to the cell > company planning on, or expecting, cell prices to drop in that period. > If they do, and you are locked in for three years, they get to keep > charging you under the older higher terms. For example, in some parts > of the country, under certain plans, weekend local air time rates are > FREE. I have GTE Mobilnet, and when they lowered the rates on my plan by $3.00 per month and allowed users to choose a peak/off-peak rate or stick with the flat rate at their option, I received the discount and was able to switch to peak/off-peak without extending my one-year contract (which had about eight months to run at the time). I DO have unlimited weekend calling, but I pay $15.00 per month for the privilege. Andrew Laurence laurence@netcom.com Certified NetWare Administrator (CNA) Oakland, California, USA CD-ROM Networking Consultant Pacific Standard Time (GMT-8) Phone: (510) 547-6647 Pager: (510) 308-1903 Fax: (510) 547-8002 ------------------------------ From: pbeker@netcom.com (Paul Beker) Subject: Re: Anyone Have Experience With LDDS/Metromedia? Organization: NETCOM On-line Communication Services (408 261-4700 guest) Date: Tue, 17 Jan 1995 23:16:39 GMT clukas@mr.net (chuck lukaszewski) writes: > I received some information from LDDS/Metromedia yesterday about their > long distance service. The rates seem entirely too good to be true, > and I'm wondering if anyone here has experience (good or bad) that > they would share. I've been using LDDS/Metromedia quite a bit in the past few months, and am generally pleased with them. The rates I have are actually through American Travel Network (a LDDS/Metromedia reseller). (800-477-9692) o ATN/LDDS/Metromedia Calling Card: - 17.5c/minute anywhere in the USA, anytime. - No per-call surcharges, no minimum. The quality of the connections on these calls occassionally seems marginal, by 1990s standards, but in my opinion, well worth saving upwards of a dollar per call. Most of my calls are to check voice mail, so ... o ATN/LDDS/Metromedia "Dial 1" residential (?) LD service: The rate schedule is split, with the five area codes with most usage being on one schedule, and other calls on the other schedule: Five NPAs Other NPAs Day (8am-5pm) 17.5c 22.5c Night (5pm-8am) 10.0c 12.5c There is a minimum monthly usage of one hour. The quality of the calls seems, again, slightly below 'big three' standards, but definitely acceptable. Call setup time is slower (2-4 sec., I would guess), and the actual ringing / busy tones sound horrible (! - dunno why). But once the connection is made, the calls sound fine. One more thing to note: You are billed separately from your local telco's bill. In other words, I receive a bill each month that contains only my calling card calls and my dial 1+ calls from home, directly from LDDS/Metromedia. My opinions only -- although this does look a lot like an ad for ATN, it isn't ... I have no connection with them or LDDS/Metromedia whatsoever. (I only wish I had thought of the no-fee calling card years ago.) Paul Beker - Atlanta, GA pbeker@netcom.com ------------------------------ From: dlr@daver.bungi.com (Dave Rand) Date: Tue, 17 Jan 1995 10:05:00 PST Subject: Re: Anyone Have Experience With LDDS/Metromedia? > I received some information from LDDS/Metromedia yesterday about their > long distance service. The rates seem entirely too good to be true, > and I'm wondering if anyone here has experience (good or bad) that > they would share. Their rates are very good. *HOWEVER* Be warned. They quoted rates of 0.27/min inbound 800, 0.25/min outbound switched to Canada for me. As most of my call volume on 800 comes from Canada, this is a significant decrease from the normal rates of 0.60-0.30. Having read the fine print on the contract -- it claims that the contract term is for service only, and does not guarantee rates -- I added a notation on my contract that the Canada rates were to be as quoted. This was a *very* good idea. First, LDDS slammed all nine of my telephone lines. I switched them úÿ back. They slammed them again. I switched them back. They slammed all but my primary outbound line, and I didn't notice for a month! Around $250 or so in PIC charges, that month. Moral -- make sure that you have *all* your lines protected, as they *will* find out all your phone numbers, even if you don't give them out. Then the bill came. The calls are rated at 0.37/minute. Customer service says "too bad". My salesman says "oops -- the rates went up *the day after* we signed up, too bad.". I said, "PUC, fraud, bait-and-switch, contracted amount!" Long discussions followed. The salesman wasn't allowed to change the contract, according to LDDS -- their problem, not mine, I pointed out to them. As of now, we are still fighting over credits, but they have agreed to give me the contracted rate, for the contracted period (one year). The dust has not settled. Be careful out there in telecom-land! Dave Rand Internet: dlr@daver.bungi.com ------------------------------ From: Barton.Bruce@camb.com Subject: Re: How Can I Encrypt a T-1? Date: 15 Jan 95 22:54:43 -0500 Organization: Cambridge Computer Associates, Inc. In article , tedh@cylink.COM (Ted Hadley) writes: > In article synchro@access1.digex.net > (Steve) writes: >> There is a company in California called Cylink. They make several >> different kinds of crypto gear for communications. I'm unable to come >> up with a telephone number for them at the moment. > Telephone number is 408-735-5800. Try 800 info for their 800 number. The cylink guy posting should have at least tooted his horn about their *EXCELENT* and *EXTENSIVE* collection of FAX-BACKable material you can just get yourself -- no salesfolk needed. They also make spread spectrum no-license needed radio links. ------------------------------ From: wtm@uhura.neoucom.edu (Bill Mayhew) Subject: Re: Bellcore Standards Question Organization: Northeastern Ohio Universities College of Medicine Date: Tue, 17 Jan 1995 19:50:36 GMT I have some doucmentation from Wescom, who makes a lot of T1 eqipment for telco applications. There are two codes for zero. The coding of the signal is mu-law 255. There are 16 chords in the same with linear values in each chord. The coding is two's-complement. As it is set up, the MSB is the sign. That yields -0 and +0 as equally valid codes of 01111111 and 11111111 respectively. The code codes are fed out of the bank as a PCM NRZ data stream. A zero bit is coded as no voltage shift in a bit time cell. A one bit is coded as a voltage level transition in either direction. No more than seven zeros in a row are permitted, or an automatic on insertion occurs to prevent the demodulator from losing lock on the incoming bit stream. This can result of one LSB resoultion on a maximal signal. Since low levels contain a lot of ones, there is no loss of resolution on small signals due to forced ones. Also, if you are using older D4 non ESF (extended superframe) equipment. A bit will be robbed every 6th frame for signalling. The robbed bits alternate between the A bit and B bit. FX Station FX Office cirucit xmt rcv dir xmt rcv A B A B A B A B busy/tip grd 0 <- 0 idle/tip open 1 <- 1 busy/ring 0 <- 0 idle/no ring 1 <- 1 idle/loop open 0 -> 0 busy/loop closed 1 -> 1 busy/ring rnd 0 -> 0 idle/ring open 1 -> 1 0 1 1 1 g strt idle 1 1 0 1 1 1 0 1 g strt busy 0 1 1 1 ESF cahnnel banks code the PCM the same way, but use a technique called forced bipolar violation to code the signalling and other control bits in the data stream and also remove the restriction of no more than seven consecutive zeros. The ESF signal is almost NRZ, but differentiates by coding two ones in a row of the *same* polarity when the offending 00 code would have occured. The dobule ones alternate so that the DC offset is still held to approximately zero (exclusive of any "sealing current" that the trnasmission eqipment injects on the circuit). You should se a lot of ones on an idle circuit. The most significant bit could be either zero or one. I don't know if Belcore has a spec on what should be done; my docs aren't that specific. The LSB is going to vary if you are on a D4 channel bank depending on the A and B bits. See the table above. Bill Mayhew NEOUCOM Computer Services Department Rootstown, OH 44272-0095 USA phone: 216-325-2511 wtm@uhura.neoucom.edu amateur radio 146.58: N8WED ------------------------------ From: rice@ttd.teradyne.com (John Rice) Subject: Re: Atlanta Airport's Pay Phones Reject 1-800 Numbers Randomly Date: 17 Jan 95 14:45:54 CST Organization: Teradyne Inc., Telecommunications Division In article , cgordon@vpnet.chi.il.us (gordon hlavenka) writes: > Payphone owners receive no revenues from 800 calls. Hence I'd imagine > that they don't rate 800-access problems very high on their list of > priorities. Hotels are getting just as bad (or worse), especially the 'majors'. I was in the Ohare Ramada last night and they wanted .50/call to call an 800 number or to call collect. John Rice K9IJ rice@ttd.teradyne.com [TELECOM Digest Editor's Note: The Ohare Ramada? Why didn't you call and say hello? Whenever Digest readers are in the Chicago area they are invited to call, or meet as long as we plan it a little ahead. PAT] ------------------------------ From: thompson@robin.tezcat.com (Bob Thompson) Subject: Re: Atlanta Airport's Pay Phones Reject 1-800 Numbers Randomly Date: Tue, 17 Jan 1995 08:31:34 GMT Organization: Tezcat.COM, Chicago In article pbeker@netcom.com (Paul Beker) writes: > [TELECOM Digest Editor's Note: You wonder what AT&T had to do to get the > account? Well I can tell you what Illinois Bell had to do to get the > O'Hare Airport account a few years ago: when the newspapers exposed the > city council members and Aviation Department employees who got the bribes > and the IBT employees who paid the bribes, there was quite a stink for > a short while, then everyone sort of forgot about it. PAT] Wasn't the epic airport struggle (some years back) the one at DFW between GenTel and AT&T. This was of course in the 'old' telephone days. Anyone remember any details. /bob/ (in Chicago, yet) ------------------------------ Subject: Where Can I Buy Telephones? From: franci.visnovic@uni-mb.si (Emilio) Date: 17 Jan 95 18:27:11 +0200 Organization: University of Maribor, Slovenia Hello, Please, can someone give me a email address of a person which sells telephones (Panasonic, Sony, AT&T). Regards, Franci! email: franci.visnovic@uni-mb.si [TELECOM Digest Editor's Note: Here in the USA we are very accustomed to seeing stores everywhere that sell phones. Any of the brand names you mentioned above are for sale anywhere you go here. All the stores have deals with one or more of the above, and quite a few others as well. Perhaps one or more of the various dealer/distributor/retail sales people reading this Digest will respond to you and assist you. PAT] ------------------------------ End of TELECOM Digest V15 #39 *****************************